Thalasseus albididorsalis
Silhouette: JJ Harrison (vectorized by T. Michael Keesey) · PhyloPic
In 3 days ~30% in a week ~60%
The West African crested tern (Thalasseus albididorsalis) is a bird species in the family Laridae. Until 2020 it was considered a subspecies of the New World royal tern, Thalasseus maximus. The West African crested tern was long thought to be a subspecies of royal tern. A study published in 2005 showed that it is more closely related to the lesser crested tern (Thalasseus bengalensis), and a 2017 publication confirmed and expanded on those results.
The West African crested tern is one of the three larger crested terns, along with royal tern and greater crested tern. Its tail is shallowly forked and the adult's bill is long and orange. It is about 50 cm (20 in) long, with a wingspan between 125–135 cm (49–53 in), and weighs 320–440 g (11–16 oz) with a mean weight of 367 g (12.9 oz). In breeding plumage its underside is white and upper parts silvery grey; the top of the head is black with a shaggy crest at the rear. As in all Thalasseus terns, the... Wikipedia →
| # | Park | Country | Daily sighting probability |
|---|
More parks will be added in future updates.
| # | City | Country | Daily sighting probability |
|---|---|---|---|
| 1 | Dakar | 🇸🇳 Senegal | |
| 2 | Luanda | 🇦🇴 Angola | |
| 3 | Freetown | 🇸🇱 Sierra Leone | |
| 4 | Serrekunda | 🇬🇲 Gambia | |
| 5 | Accra | 🇬🇭 Ghana |
With luck
About 10% of wildlife watchers report a West African Crested Tern sighting in Luanda on a given day, based on 19 verified sightings from GBIF citizen-science data. It is the 18th most-seen of the 45 birds we can rate there. Over three days the chance rises to about 30%, and over a week to about 60%, if each day is a fresh chance.
November
In that month about 30% of wildlife watchers report a West African Crested Tern in Luanda on a given day, against under 5% in July, the lowest month. February–March, June and December have too few records to rate.
Between 1 and 4 pm
Across all the parks we cover, that three-hour window holds the most West African Crested Tern sightings with a recorded time, and about 9 in 10 of them come between 6 am and 6 pm: it is a daytime animal.
2nd of 5
Of the 5 cities where we can rate West African Crested Tern sightings, Luanda ranks 2nd at about 10%. The best odds are in Dakar (Senegal, about 40%).
GBIF citizen-science records
It is estimated from how often the West African Crested Tern is recorded against all the birds logged in Luanda (19 verified sightings), calibrated against known sighting rates. Figures are rounded to the nearest 10% because citizen-science data supports honest approximations, not decimals, and months with records from fewer than five people show "—". How it works.
